"As a child, Maria Mitchell longed to see beyond her little island of Nantucket. With help from her father, she discovered that, if you knew how to read them, the stars could tell you where you were -- and where you needed to go. Maria spent hours on the roof of her house scanning the sky -- finding constellations, nebulae, meteors, double stars. When the King of Denmark offered a prize to the first person to find a new comet, she did just that. In...